This K08 research and training award will enable the PI to develop skills as an independent clinical scientist using advanced research methodology to ultimately (a) uncover new mechanisms of action underlying the association between acute alcohol and risky sexual behavior among men who have sex with men (MSM), and (b) use that knowledge to refine preventative interventions targeting alcohol-related HIV-risk behavior within this high-priority population.. Preliminary findings suggest that domain-general impulsive delay discounting is associated with sexual risk-taking in the context of co-occurring alcohol use. Measures of SSDD tend to outperform domain-general discounting measures in terms of strength of association with risky sexual behavior. The proposed project would be the first to examine the causal effects of acute alcohol on SSDD, and subsequent effects on sexual decision making among MSM. Formative research (Phase 1) will involve qualitative exploration of men's personal experience of sexual impulsivity, as well as qualitative feedback to adapt and refine our experimental paradigm to match the target population. Pilot research (Phase 2) will be conducted to bridge the formative phase and full experimental investigation (Phase 3). Adult MSM who are single, sexually active, and engage in heavy drinking will be recruited from the local community to participate in the qualitative focus groups (Phase 1; N=30-48), pilot testing of experimental protocol (Phase 2; N=12), and the full experimental trial (Phase 3; N=180). The full single-session experiment will employ an alcohol/placebo/nonalcohol design with random assignment to one of three conditions (i.e., alcohol at 0.8g/kg dose, placebo, and true control) to examine the acute effects of alcohol (i.e., both pharmacological and expectancy) on SSDD, and the subsequent effects on risky sexual decision making (i.e., intention to engage in unprotected anal intercourse). This research will lead to subsequent grant applications to (a) extend this line of human laboratory research, and (b) develop a behavioral economic supplement to brief preventative intervention targeting alcohol-related HIV risk behavior. The PI will work with a highly skilled mentorship team (Drs. Peter Monti, Don Operario, James MacKillop, James Murphy, and David Jarmolowicz) to build four areas of expertise relevant to this research agenda: 1) experimental and qualitative research methodology; 2) behavioral economics of sexual decision making; 3) health disparities in MSM populations; and 4) preventative intervention, with specific emphasis on HIV risk behavior. This K08 proposal addresses a key priority in national public health, and the science of alcohol- related HIV-risk behavior, and will fully prepare the PI for an independent research career in clinical science.